To see some detailed info about which users are currently connected to your DB2 database server (including the SQL statements they are running), you can use the following query (tested with DB2 9.7, fixpack 3a):
WITH a AS (SELECT a.application_handle, a.system_auth_id, a.application_name, a.client_wrkstnname, a.workload_name, a.workload_occurrence_state, b.activity_id, b.uow_id, b.local_start_time, b.activity_state, b.activity_type, b.total_cpu_time, b.rows_read, b.rows_returned, b.query_cost_estimate, b.direct_reads, b.direct_writes
FROM TABLE(wlm_get_service_class_workload_occurrences_v97(NULL, NULL, NULL)) a
LEFT JOIN TABLE(wlm_get_workload_occurrence_activities_v97(NULL, NULL)) b ON a.application_handle = b.application_handle),
b AS (SELECT t.*
FROM TABLE(mon_get_activity_details(FOR EACH ROW OF (SELECT application_handle, uow_id, activity_id, NULL FROM a WHERE activity_id > 0))) t),
c AS (SELECT x."activity_id" activity_id, x."uow_id" uow_id, x."stmt_text" stmt_text
FROM b,
XMLTABLE(XMLNAMESPACES(DEFAULT 'http://www.ibm.com/xmlns/prod/db2/mon'), '$m/db2_activity_details' PASSING XMLPARSE(DOCUMENT b.details) AS "m" COLUMNS
"activity_id" INTEGER PATH 'activity_id',
"uow_id" INTEGER PATH 'uow_id',
"stmt_text" VARCHAR(1024) PATH 'stmt_text') x)
SELECT a.*, TRANSLATE(c.stmt_text, ' ', CHR(10)) stmt_text
FROM a
LEFT JOIN c ON a.activity_id = c.activity_id AND a.uow_id = c.uow_id
WHERE stmt_text IS NULL OR SUBSTR(stmt_text, 1, 40) <> 'WITH a AS (SELECT a.application_handle, '
ORDER BY application_handle, a.activity_id